DIESEL OXIDIZING CATALYTIC CONVERTER

• US 20190314791A1
• Filed: 07/13/2017
• Published: 10/17/2019
• Est. Priority Date: 07/19/2016
• Status: Active Grant

• Current Assignee: Umicore AG & Company KG (Umicore S.A.)
• Original Assignee: Umicore AG & Company KG (Umicore S.A.)
• Inventors: HENGST, Christoph, REITH, Christoph, SCHIFFER, Michael
• Granted Patent: US 11,052,378 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/204 Alkaline earth metals
• CPC Class Codes: B01D 2255/2042 Barium
• CPC Class Codes: B01D 2255/20707 Titanium
• CPC Class Codes: B01D 2255/2092 Aluminium
• CPC Class Codes: B01D 2255/9022 Two layers
• CPC Class Codes: B01D 2255/9032 Two zones
• CPC Class Codes: B01D 2255/915 Catalyst supported on particulate filters
• CPC Class Codes: B01D 2255/9202 Linear dimensions
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01D 53/9468 in different layers
• CPC Class Codes: B01D 53/9477 with catalysts positioned on separate bricks, e.g. exhaust systems
• CPC Class Codes: B01J 23/10 of rare earths
• CPC Class Codes: B01J 23/44 Palladium
• CPC Class Codes: B01J 23/63 with rare earths or actinides
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/24 Strontium
• CPC Class Codes: B01J 2523/31 : Aluminium
• CPC Class Codes: B01J 2523/3706 : Lanthanum
• CPC Class Codes: B01J 2523/824 : Palladium
• CPC Class Codes: B01J 2523/828 : Platinum
• CPC Class Codes: B01J 35/19 : Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/56 : Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 37/0215 : Coating
• CPC Class Codes: B01J 37/0234 : Impregnation and coating simultaneously
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: F01N 2370/02 : used in catalytic reactors
• CPC Class Codes: F01N 2510/0684 : having more than one coating layer, e.g. multi-layered coatings
• CPC Class Codes: F01N 3/035 : with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/103 : Oxidation catalysts for HC and CO only
• CPC Class Codes: F01N 3/28 : Construction of catalytic reactors
• CPC Class Codes: F01N 3/2828 : Ceramic multi-channel monoliths, e.g. honeycombs

Abstract

The present invention relates to a diesel oxidizing catalytic converter which comprises a supporting body with a length L which extends between a first end surface a and a second end surface b, and catalytically active material zones A and B of different composition which are arranged on the supporting body, wherein —material zone A comprises palladium or platinum and palladium in a weight ratio Pt:Pd of <1 and, starting from the end surface a, extends to from 20% to 80% of the length L, and —material zone B comprises platinum and palladium in a weight ratio Pt:Pd of <10 and extends to from 80% to 100% of the length L, and wherein material zone B is arranged above material zone A and the weight ratio Pt:Pd in relation to the material zones A and B is from 1.5 to 3.0.

Claims

1. Diesel oxidation catalyst comprising

a carrier body having a length L extending between a first end face a and a second end face b, and

variously composed catalytically active material zones A and B arranged on the carrier body, wherein

material zone A contains palladium or platinum and palladium in a weight ratio Pt:

Pd of ≤

1 and extends starting from end face a to 20 to 80% of length L, and

material zone B contains platinum and palladium in a weight ratio Pt;

Pd of <

10 and extends to 80 to 100% of length L, and

wherein material zone B is arranged above material zone A and the weight ratio Pt;

Pd relative to the material zones A and B is 1.5 to 3.0.

2. The diesel oxidation catalyst according to claim 1, wherein in the material zones A and B, palladium or platinum and palladium are present on a carrier oxide.

3. The diesel oxidation catalyst according to claim 2, wherein the carrier oxides in material zones A and C are identical to or different from one another and are selected from the group consisting of aluminum oxide, doped aluminum oxide, silicon oxide, titanium dioxide and mixed oxides of one or more thereof.

4. The diesel oxidation catalyst according to claim 1, wherein material zone A contains an alkaline earth metal.

5. The diesel oxidation catalyst according to claim 4, wherein the alkaline earth metal in material zone A is strontium or barium or strontium and barium.

6. The diesel oxidation catalyst according to claim 1, wherein the length of the material zone Bis 95% or 100% of the total length L of the carrier body.

7. A method for treating diesel exhaust gases, wherein the diesel exhaust gas is conducted through a diesel oxidation catalyst according to claim 1, wherein the diesel exhaust gas flows into the carrier body at end face a and flows out of the carrier body at end face b.

8. A device for purification of exhaust gases from diesel engines having a diesel oxidation catalyst according to claim 1.

9. A device for purification of exhaust uses from diesel engines having a diesel oxidation catalyst according to claim 1 wherein the diesel oxidation catalyst is arranged upstream of a diesel particulate filter and/or a catalyst for the selective catalytic reduction of nitrogen oxides.